; NOTE: Assertions have been autogenerated by utils/update_test_checks.py ; RUN: opt -indvars -S < %s | FileCheck %s target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64" @X = external global [0 x double] ; Indvars should be able to simplify simple comparisons involving ; induction variables. define void @foo(i64 %n, i32* nocapture %p) nounwind { ; CHECK-LABEL: @foo( ; CHECK-NEXT: entry: ; CHECK-NEXT: [[CMP9:%.*]] = icmp sgt i64 [[N:%.*]], 0 ; CHECK-NEXT: br i1 [[CMP9]], label [[PRE:%.*]], label [[RETURN:%.*]] ; CHECK: pre: ; CHECK-NEXT: [[T3:%.*]] = load i32, i32* [[P:%.*]], align 4 ; CHECK-NEXT: [[TOBOOL_NOT:%.*]] = icmp ne i32 [[T3]], 0 ; CHECK-NEXT: br label [[LOOP:%.*]] ; CHECK: loop: ; CHECK-NEXT: [[I:%.*]] = phi i64 [ 0, [[PRE]] ], [ [[INC:%.*]], [[FOR_INC:%.*]] ] ; CHECK-NEXT: [[COND:%.*]] = and i1 [[TOBOOL_NOT]], true ; CHECK-NEXT: br i1 [[COND]], label [[IF_THEN:%.*]], label [[FOR_INC]] ; CHECK: if.then: ; CHECK-NEXT: [[ARRAYIDX:%.*]] = getelementptr [0 x double], [0 x double]* @X, i64 0, i64 [[I]] ; CHECK-NEXT: store double 3.200000e+00, double* [[ARRAYIDX]], align 8 ; CHECK-NEXT: br label [[FOR_INC]] ; CHECK: for.inc: ; CHECK-NEXT: [[INC]] = add nuw nsw i64 [[I]], 1 ; CHECK-NEXT: [[EXITCOND1:%.*]] = icmp eq i64 [[INC]], [[N]] ; CHECK-NEXT: br i1 [[EXITCOND1]], label [[RETURN_LOOPEXIT:%.*]], label [[LOOP]] ; CHECK: return.loopexit: ; CHECK-NEXT: br label [[RETURN]] ; CHECK: return: ; CHECK-NEXT: ret void ; entry: %cmp9 = icmp sgt i64 %n, 0 br i1 %cmp9, label %pre, label %return pre: %t3 = load i32, i32* %p %tobool.not = icmp ne i32 %t3, 0 br label %loop loop: %i = phi i64 [ 0, %pre ], [ %inc, %for.inc ] %cmp6 = icmp slt i64 %i, %n %cond = and i1 %tobool.not, %cmp6 br i1 %cond, label %if.then, label %for.inc if.then: %arrayidx = getelementptr [0 x double], [0 x double]* @X, i64 0, i64 %i store double 3.200000e+00, double* %arrayidx br label %for.inc for.inc: %inc = add nsw i64 %i, 1 %exitcond = icmp sge i64 %inc, %n br i1 %exitcond, label %return, label %loop return: ret void } ; Don't eliminate an icmp that's contributing to the loop exit test though. define i32 @_ZNK4llvm5APInt3ultERKS0_(i32 %tmp2.i1, i64** %tmp65, i64** %tmp73, i64** %tmp82, i64** %tmp90) { ; CHECK-LABEL: @_ZNK4llvm5APInt3ultERKS0_( ; CHECK-NEXT: entry: ; CHECK-NEXT: br label [[BB18:%.*]] ; CHECK: bb13: ; CHECK-NEXT: [[TMP66:%.*]] = load i64*, i64** [[TMP65:%.*]], align 4 ; CHECK-NEXT: [[TMP68:%.*]] = getelementptr inbounds i64, i64* [[TMP66]], i32 [[I:%.*]] ; CHECK-NEXT: [[TMP69:%.*]] = load i64, i64* [[TMP68]], align 4 ; CHECK-NEXT: [[TMP74:%.*]] = load i64*, i64** [[TMP73:%.*]], align 4 ; CHECK-NEXT: [[TMP76:%.*]] = getelementptr inbounds i64, i64* [[TMP74]], i32 [[I]] ; CHECK-NEXT: [[TMP77:%.*]] = load i64, i64* [[TMP76]], align 4 ; CHECK-NEXT: [[TMP78:%.*]] = icmp ugt i64 [[TMP69]], [[TMP77]] ; CHECK-NEXT: br i1 [[TMP78]], label [[BB20_LOOPEXIT:%.*]], label [[BB15:%.*]] ; CHECK: bb15: ; CHECK-NEXT: [[TMP83:%.*]] = load i64*, i64** [[TMP82:%.*]], align 4 ; CHECK-NEXT: [[TMP85:%.*]] = getelementptr inbounds i64, i64* [[TMP83]], i32 [[I]] ; CHECK-NEXT: [[TMP86:%.*]] = load i64, i64* [[TMP85]], align 4 ; CHECK-NEXT: [[TMP91:%.*]] = load i64*, i64** [[TMP90:%.*]], align 4 ; CHECK-NEXT: [[TMP93:%.*]] = getelementptr inbounds i64, i64* [[TMP91]], i32 [[I]] ; CHECK-NEXT: [[TMP94:%.*]] = load i64, i64* [[TMP93]], align 4 ; CHECK-NEXT: [[TMP95:%.*]] = icmp ult i64 [[TMP86]], [[TMP94]] ; CHECK-NEXT: br i1 [[TMP95]], label [[BB20_LOOPEXIT]], label [[BB17:%.*]] ; CHECK: bb17: ; CHECK-NEXT: [[TMP97:%.*]] = add nsw i32 [[I]], -1 ; CHECK-NEXT: br label [[BB18]] ; CHECK: bb18: ; CHECK-NEXT: [[I]] = phi i32 [ [[TMP2_I1:%.*]], [[ENTRY:%.*]] ], [ [[TMP97]], [[BB17]] ] ; CHECK-NEXT: [[TMP99:%.*]] = icmp sgt i32 [[I]], -1 ; CHECK-NEXT: br i1 [[TMP99]], label [[BB13:%.*]], label [[BB20_LOOPEXIT]] ; CHECK: bb20.loopexit: ; CHECK-NEXT: [[TMP_0_PH:%.*]] = phi i32 [ 0, [[BB18]] ], [ 1, [[BB15]] ], [ 0, [[BB13]] ] ; CHECK-NEXT: ret i32 [[TMP_0_PH]] ; entry: br label %bb18 bb13: %tmp66 = load i64*, i64** %tmp65, align 4 %tmp68 = getelementptr inbounds i64, i64* %tmp66, i32 %i %tmp69 = load i64, i64* %tmp68, align 4 %tmp74 = load i64*, i64** %tmp73, align 4 %tmp76 = getelementptr inbounds i64, i64* %tmp74, i32 %i %tmp77 = load i64, i64* %tmp76, align 4 %tmp78 = icmp ugt i64 %tmp69, %tmp77 br i1 %tmp78, label %bb20.loopexit, label %bb15 bb15: %tmp83 = load i64*, i64** %tmp82, align 4 %tmp85 = getelementptr inbounds i64, i64* %tmp83, i32 %i %tmp86 = load i64, i64* %tmp85, align 4 %tmp91 = load i64*, i64** %tmp90, align 4 %tmp93 = getelementptr inbounds i64, i64* %tmp91, i32 %i %tmp94 = load i64, i64* %tmp93, align 4 %tmp95 = icmp ult i64 %tmp86, %tmp94 br i1 %tmp95, label %bb20.loopexit, label %bb17 bb17: %tmp97 = add nsw i32 %i, -1 br label %bb18 bb18: %i = phi i32 [ %tmp2.i1, %entry ], [ %tmp97, %bb17 ] %tmp99 = icmp sgt i32 %i, -1 br i1 %tmp99, label %bb13, label %bb20.loopexit bb20.loopexit: %tmp.0.ph = phi i32 [ 0, %bb18 ], [ 1, %bb15 ], [ 0, %bb13 ] ret i32 %tmp.0.ph } ; Indvars should eliminate the icmp here. define void @func_10() nounwind { ; CHECK-LABEL: @func_10( ; CHECK-NEXT: entry: ; CHECK-NEXT: br label [[LOOP:%.*]] ; CHECK: loop: ; CHECK-NEXT: [[INDVARS_IV:%.*]] = phi i64 [ [[INDVARS_IV_NEXT:%.*]], [[LOOP]] ], [ 0, [[ENTRY:%.*]] ] ; CHECK-NEXT: store i64 [[INDVARS_IV]], i64* null, align 8 ; CHECK-NEXT: [[INDVARS_IV_NEXT]] = add nuw nsw i64 [[INDVARS_IV]], 1 ; CHECK-NEXT: br i1 false, label [[LOOP]], label [[RETURN:%.*]] ; CHECK: return: ; CHECK-NEXT: ret void ; entry: br label %loop loop: %i = phi i32 [ %i.next, %loop ], [ 0, %entry ] %t0 = icmp slt i32 %i, 0 %t1 = zext i1 %t0 to i32 %t2 = add i32 %t1, %i %u3 = zext i32 %t2 to i64 store i64 %u3, i64* null %i.next = add i32 %i, 1 br i1 undef, label %loop, label %return return: ret void } ; PR14432 ; Indvars should not turn the second loop into an infinite one. define i32 @func_11() nounwind uwtable { ; CHECK-LABEL: @func_11( ; CHECK-NEXT: entry: ; CHECK-NEXT: br label [[FORCOND:%.*]] ; CHECK: forcond: ; CHECK-NEXT: br i1 false, label [[NOASSERT:%.*]], label [[FORCOND38_PREHEADER:%.*]] ; CHECK: forcond38.preheader: ; CHECK-NEXT: br label [[FORCOND38:%.*]] ; CHECK: noassert: ; CHECK-NEXT: br i1 true, label [[FORCOND]], label [[ASSERT33:%.*]] ; CHECK: assert33: ; CHECK-NEXT: tail call void @llvm.trap() ; CHECK-NEXT: unreachable ; CHECK: forcond38: ; CHECK-NEXT: br i1 false, label [[NOASSERT68:%.*]], label [[UNROLLEDEND:%.*]] ; CHECK: noassert68: ; CHECK-NEXT: br i1 true, label [[FORCOND38]], label [[ASSERT77:%.*]] ; CHECK: assert77: ; CHECK-NEXT: tail call void @llvm.trap() ; CHECK-NEXT: unreachable ; CHECK: unrolledend: ; CHECK-NEXT: ret i32 0 ; entry: br label %forcond forcond: ; preds = %noassert, %entry %__key6.0 = phi i32 [ 2, %entry ], [ %tmp37, %noassert ] %tmp5 = icmp slt i32 %__key6.0, 10 br i1 %tmp5, label %noassert, label %forcond38.preheader forcond38.preheader: ; preds = %forcond br label %forcond38 noassert: ; preds = %forbody %tmp13 = sdiv i32 -32768, %__key6.0 %tmp2936 = shl i32 %tmp13, 24 %sext23 = shl i32 %tmp13, 24 %tmp32 = icmp eq i32 %tmp2936, %sext23 %tmp37 = add i32 %__key6.0, 1 br i1 %tmp32, label %forcond, label %assert33 assert33: ; preds = %noassert tail call void @llvm.trap() unreachable forcond38: ; preds = %noassert68, %forcond38.preheader %__key8.0 = phi i32 [ %tmp81, %noassert68 ], [ 2, %forcond38.preheader ] %tmp46 = icmp slt i32 %__key8.0, 10 br i1 %tmp46, label %noassert68, label %unrolledend noassert68: ; preds = %forbody39 %tmp57 = sdiv i32 -32768, %__key8.0 %sext34 = shl i32 %tmp57, 16 %sext21 = shl i32 %tmp57, 16 %tmp76 = icmp eq i32 %sext34, %sext21 %tmp81 = add i32 %__key8.0, 1 br i1 %tmp76, label %forcond38, label %assert77 assert77: ; preds = %noassert68 tail call void @llvm.trap() unreachable unrolledend: ; preds = %forcond38 ret i32 0 } define i32 @func_11_flipped() nounwind uwtable { ; CHECK-LABEL: @func_11_flipped( ; CHECK-NEXT: entry: ; CHECK-NEXT: br label [[FORCOND:%.*]] ; CHECK: forcond: ; CHECK-NEXT: br i1 true, label [[FORCOND38_PREHEADER:%.*]], label [[NOASSERT:%.*]] ; CHECK: forcond38.preheader: ; CHECK-NEXT: br label [[FORCOND38:%.*]] ; CHECK: noassert: ; CHECK-NEXT: br i1 true, label [[FORCOND]], label [[ASSERT33:%.*]] ; CHECK: assert33: ; CHECK-NEXT: tail call void @llvm.trap() ; CHECK-NEXT: unreachable ; CHECK: forcond38: ; CHECK-NEXT: br i1 false, label [[NOASSERT68:%.*]], label [[UNROLLEDEND:%.*]] ; CHECK: noassert68: ; CHECK-NEXT: br i1 true, label [[FORCOND38]], label [[ASSERT77:%.*]] ; CHECK: assert77: ; CHECK-NEXT: tail call void @llvm.trap() ; CHECK-NEXT: unreachable ; CHECK: unrolledend: ; CHECK-NEXT: ret i32 0 ; entry: br label %forcond forcond: ; preds = %noassert, %entry %__key6.0 = phi i32 [ 2, %entry ], [ %tmp37, %noassert ] %tmp5 = icmp sge i32 %__key6.0, 10 br i1 %tmp5, label %forcond38.preheader, label %noassert forcond38.preheader: ; preds = %forcond br label %forcond38 noassert: ; preds = %forbody %tmp13 = sdiv i32 -32768, %__key6.0 %tmp2936 = shl i32 %tmp13, 24 %sext23 = shl i32 %tmp13, 24 %tmp32 = icmp eq i32 %tmp2936, %sext23 %tmp37 = add i32 %__key6.0, 1 br i1 %tmp32, label %forcond, label %assert33 assert33: ; preds = %noassert tail call void @llvm.trap() unreachable forcond38: ; preds = %noassert68, %forcond38.preheader %__key8.0 = phi i32 [ %tmp81, %noassert68 ], [ 2, %forcond38.preheader ] %tmp46 = icmp slt i32 %__key8.0, 10 br i1 %tmp46, label %noassert68, label %unrolledend noassert68: ; preds = %forbody39 %tmp57 = sdiv i32 -32768, %__key8.0 %sext34 = shl i32 %tmp57, 16 %sext21 = shl i32 %tmp57, 16 %tmp76 = icmp eq i32 %sext34, %sext21 %tmp81 = add i32 %__key8.0, 1 br i1 %tmp76, label %forcond38, label %assert77 assert77: ; preds = %noassert68 tail call void @llvm.trap() unreachable unrolledend: ; preds = %forcond38 ret i32 0 } declare void @llvm.trap() noreturn nounwind ; In this case the second loop only has a single iteration, fold the header away define i32 @func_12() nounwind uwtable { ; CHECK-LABEL: @func_12( ; CHECK-NEXT: entry: ; CHECK-NEXT: br label [[FORCOND:%.*]] ; CHECK: forcond: ; CHECK-NEXT: br i1 false, label [[NOASSERT:%.*]], label [[FORCOND38_PREHEADER:%.*]] ; CHECK: forcond38.preheader: ; CHECK-NEXT: br label [[FORCOND38:%.*]] ; CHECK: noassert: ; CHECK-NEXT: br i1 true, label [[FORCOND]], label [[ASSERT33:%.*]] ; CHECK: assert33: ; CHECK-NEXT: tail call void @llvm.trap() ; CHECK-NEXT: unreachable ; CHECK: forcond38: ; CHECK-NEXT: br i1 true, label [[NOASSERT68:%.*]], label [[UNROLLEDEND:%.*]] ; CHECK: noassert68: ; CHECK-NEXT: br i1 false, label [[FORCOND38]], label [[ASSERT77:%.*]] ; CHECK: assert77: ; CHECK-NEXT: tail call void @llvm.trap() ; CHECK-NEXT: unreachable ; CHECK: unrolledend: ; CHECK-NEXT: ret i32 0 ; entry: br label %forcond forcond: ; preds = %noassert, %entry %__key6.0 = phi i32 [ 2, %entry ], [ %tmp37, %noassert ] %tmp5 = icmp slt i32 %__key6.0, 10 br i1 %tmp5, label %noassert, label %forcond38.preheader forcond38.preheader: ; preds = %forcond br label %forcond38 noassert: ; preds = %forbody %tmp13 = sdiv i32 -32768, %__key6.0 %tmp2936 = shl i32 %tmp13, 24 %sext23 = shl i32 %tmp13, 24 %tmp32 = icmp eq i32 %tmp2936, %sext23 %tmp37 = add i32 %__key6.0, 1 br i1 %tmp32, label %forcond, label %assert33 assert33: ; preds = %noassert tail call void @llvm.trap() unreachable forcond38: ; preds = %noassert68, %forcond38.preheader %__key8.0 = phi i32 [ %tmp81, %noassert68 ], [ 2, %forcond38.preheader ] %tmp46 = icmp slt i32 %__key8.0, 10 br i1 %tmp46, label %noassert68, label %unrolledend noassert68: ; preds = %forbody39 %tmp57 = sdiv i32 -32768, %__key8.0 %sext34 = shl i32 %tmp57, 16 %sext21 = shl i32 %tmp57, 16 %tmp76 = icmp ne i32 %sext34, %sext21 %tmp81 = add i32 %__key8.0, 1 br i1 %tmp76, label %forcond38, label %assert77 assert77: ; preds = %noassert68 tail call void @llvm.trap() unreachable unrolledend: ; preds = %forcond38 ret i32 0 } declare void @side_effect() define void @func_13(i32* %len.ptr) { ; CHECK-LABEL: @func_13( ; CHECK-NEXT: entry: ; CHECK-NEXT: [[LEN:%.*]] = load i32, i32* [[LEN_PTR:%.*]], align 4, [[RNG0:!range !.*]] ; CHECK-NEXT: [[LEN_IS_ZERO:%.*]] = icmp eq i32 [[LEN]], 0 ; CHECK-NEXT: br i1 [[LEN_IS_ZERO]], label [[LEAVE:%.*]], label [[LOOP_PREHEADER:%.*]] ; CHECK: loop.preheader: ; CHECK-NEXT: br label [[LOOP:%.*]] ; CHECK: loop: ; CHECK-NEXT: [[IV:%.*]] = phi i32 [ [[IV_INC:%.*]], [[BE:%.*]] ], [ 0, [[LOOP_PREHEADER]] ] ; CHECK-NEXT: call void @side_effect() ; CHECK-NEXT: [[IV_INC]] = add nuw nsw i32 [[IV]], 1 ; CHECK-NEXT: br i1 true, label [[BE]], label [[LEAVE_LOOPEXIT:%.*]] ; CHECK: be: ; CHECK-NEXT: call void @side_effect() ; CHECK-NEXT: [[EXITCOND:%.*]] = icmp ne i32 [[IV_INC]], [[LEN]] ; CHECK-NEXT: br i1 [[EXITCOND]], label [[LOOP]], label [[LEAVE_LOOPEXIT]] ; CHECK: leave.loopexit: ; CHECK-NEXT: br label [[LEAVE]] ; CHECK: leave: ; CHECK-NEXT: ret void ; entry: %len = load i32, i32* %len.ptr, !range !0 %len.sub.1 = add i32 %len, -1 %len.is.zero = icmp eq i32 %len, 0 br i1 %len.is.zero, label %leave, label %loop loop: %iv = phi i32 [ 0, %entry ], [ %iv.inc, %be ] call void @side_effect() %iv.inc = add i32 %iv, 1 %iv.cmp = icmp ult i32 %iv, %len br i1 %iv.cmp, label %be, label %leave be: call void @side_effect() %be.cond = icmp ult i32 %iv, %len.sub.1 br i1 %be.cond, label %loop, label %leave leave: ret void } define void @func_14(i32* %len.ptr) { ; CHECK-LABEL: @func_14( ; CHECK-NEXT: entry: ; CHECK-NEXT: [[LEN:%.*]] = load i32, i32* [[LEN_PTR:%.*]], align 4, [[RNG0]] ; CHECK-NEXT: [[LEN_IS_ZERO:%.*]] = icmp eq i32 [[LEN]], 0 ; CHECK-NEXT: [[LEN_IS_INT_MIN:%.*]] = icmp eq i32 [[LEN]], -2147483648 ; CHECK-NEXT: [[NO_ENTRY:%.*]] = or i1 [[LEN_IS_ZERO]], [[LEN_IS_INT_MIN]] ; CHECK-NEXT: br i1 [[NO_ENTRY]], label [[LEAVE:%.*]], label [[LOOP_PREHEADER:%.*]] ; CHECK: loop.preheader: ; CHECK-NEXT: br label [[LOOP:%.*]] ; CHECK: loop: ; CHECK-NEXT: [[IV:%.*]] = phi i32 [ [[IV_INC:%.*]], [[BE:%.*]] ], [ 0, [[LOOP_PREHEADER]] ] ; CHECK-NEXT: call void @side_effect() ; CHECK-NEXT: [[IV_INC]] = add nuw nsw i32 [[IV]], 1 ; CHECK-NEXT: br i1 true, label [[BE]], label [[LEAVE_LOOPEXIT:%.*]] ; CHECK: be: ; CHECK-NEXT: call void @side_effect() ; CHECK-NEXT: [[EXITCOND:%.*]] = icmp ne i32 [[IV_INC]], [[LEN]] ; CHECK-NEXT: br i1 [[EXITCOND]], label [[LOOP]], label [[LEAVE_LOOPEXIT]] ; CHECK: leave.loopexit: ; CHECK-NEXT: br label [[LEAVE]] ; CHECK: leave: ; CHECK-NEXT: ret void ; entry: %len = load i32, i32* %len.ptr, !range !0 %len.sub.1 = add i32 %len, -1 %len.is.zero = icmp eq i32 %len, 0 %len.is.int_min = icmp eq i32 %len, 2147483648 %no.entry = or i1 %len.is.zero, %len.is.int_min br i1 %no.entry, label %leave, label %loop loop: %iv = phi i32 [ 0, %entry ], [ %iv.inc, %be ] call void @side_effect() %iv.inc = add i32 %iv, 1 %iv.cmp = icmp slt i32 %iv, %len br i1 %iv.cmp, label %be, label %leave be: call void @side_effect() %be.cond = icmp slt i32 %iv, %len.sub.1 br i1 %be.cond, label %loop, label %leave leave: ret void } define void @func_15(i32* %len.ptr) { ; CHECK-LABEL: @func_15( ; CHECK-NEXT: entry: ; CHECK-NEXT: [[LEN:%.*]] = load i32, i32* [[LEN_PTR:%.*]], align 4, [[RNG0]] ; CHECK-NEXT: [[LEN_ADD_1:%.*]] = add i32 [[LEN]], 1 ; CHECK-NEXT: [[LEN_ADD_1_IS_ZERO:%.*]] = icmp eq i32 [[LEN_ADD_1]], 0 ; CHECK-NEXT: br i1 [[LEN_ADD_1_IS_ZERO]], label [[LEAVE:%.*]], label [[LOOP_PREHEADER:%.*]] ; CHECK: loop.preheader: ; CHECK-NEXT: br label [[LOOP:%.*]] ; CHECK: loop: ; CHECK-NEXT: [[IV:%.*]] = phi i32 [ [[IV_INC:%.*]], [[BE:%.*]] ], [ 0, [[LOOP_PREHEADER]] ] ; CHECK-NEXT: call void @side_effect() ; CHECK-NEXT: [[IV_INC]] = add nuw nsw i32 [[IV]], 1 ; CHECK-NEXT: br i1 true, label [[BE]], label [[LEAVE_LOOPEXIT:%.*]] ; CHECK: be: ; CHECK-NEXT: call void @side_effect() ; CHECK-NEXT: [[EXITCOND:%.*]] = icmp ne i32 [[IV_INC]], [[LEN_ADD_1]] ; CHECK-NEXT: br i1 [[EXITCOND]], label [[LOOP]], label [[LEAVE_LOOPEXIT]] ; CHECK: leave.loopexit: ; CHECK-NEXT: br label [[LEAVE]] ; CHECK: leave: ; CHECK-NEXT: ret void ; entry: %len = load i32, i32* %len.ptr, !range !0 %len.add.1 = add i32 %len, 1 %len.add.1.is.zero = icmp eq i32 %len.add.1, 0 br i1 %len.add.1.is.zero, label %leave, label %loop loop: %iv = phi i32 [ 0, %entry ], [ %iv.inc, %be ] call void @side_effect() %iv.inc = add i32 %iv, 1 %iv.cmp = icmp ult i32 %iv, %len.add.1 br i1 %iv.cmp, label %be, label %leave be: call void @side_effect() %be.cond = icmp ult i32 %iv, %len br i1 %be.cond, label %loop, label %leave leave: ret void } define void @func_16(i32* %len.ptr) { ; CHECK-LABEL: @func_16( ; CHECK-NEXT: entry: ; CHECK-NEXT: [[LEN:%.*]] = load i32, i32* [[LEN_PTR:%.*]], align 4, [[RNG0]] ; CHECK-NEXT: [[LEN_ADD_5:%.*]] = add i32 [[LEN]], 5 ; CHECK-NEXT: [[ENTRY_COND_0:%.*]] = icmp slt i32 [[LEN]], 2147483643 ; CHECK-NEXT: [[ENTRY_COND_1:%.*]] = icmp slt i32 4, [[LEN_ADD_5]] ; CHECK-NEXT: [[ENTRY_COND:%.*]] = and i1 [[ENTRY_COND_0]], [[ENTRY_COND_1]] ; CHECK-NEXT: br i1 [[ENTRY_COND]], label [[LOOP_PREHEADER:%.*]], label [[LEAVE:%.*]] ; CHECK: loop.preheader: ; CHECK-NEXT: [[TMP0:%.*]] = add nuw nsw i32 [[LEN]], 1 ; CHECK-NEXT: br label [[LOOP:%.*]] ; CHECK: loop: ; CHECK-NEXT: [[IV:%.*]] = phi i32 [ [[IV_INC:%.*]], [[BE:%.*]] ], [ 0, [[LOOP_PREHEADER]] ] ; CHECK-NEXT: call void @side_effect() ; CHECK-NEXT: [[IV_INC]] = add nuw nsw i32 [[IV]], 1 ; CHECK-NEXT: br i1 true, label [[BE]], label [[LEAVE_LOOPEXIT:%.*]] ; CHECK: be: ; CHECK-NEXT: call void @side_effect() ; CHECK-NEXT: [[EXITCOND:%.*]] = icmp ne i32 [[IV_INC]], [[TMP0]] ; CHECK-NEXT: br i1 [[EXITCOND]], label [[LOOP]], label [[LEAVE_LOOPEXIT]] ; CHECK: leave.loopexit: ; CHECK-NEXT: br label [[LEAVE]] ; CHECK: leave: ; CHECK-NEXT: ret void ; entry: %len = load i32, i32* %len.ptr, !range !0 %len.add.5 = add i32 %len, 5 %entry.cond.0 = icmp slt i32 %len, 2147483643 %entry.cond.1 = icmp slt i32 4, %len.add.5 %entry.cond = and i1 %entry.cond.0, %entry.cond.1 br i1 %entry.cond, label %loop, label %leave loop: %iv = phi i32 [ 0, %entry ], [ %iv.inc, %be ] call void @side_effect() %iv.inc = add i32 %iv, 1 %iv.add.4 = add i32 %iv, 4 %iv.cmp = icmp slt i32 %iv.add.4, %len.add.5 br i1 %iv.cmp, label %be, label %leave be: call void @side_effect() %be.cond = icmp slt i32 %iv, %len br i1 %be.cond, label %loop, label %leave leave: ret void } define void @func_17(i32* %len.ptr) { ; CHECK-LABEL: @func_17( ; CHECK-NEXT: entry: ; CHECK-NEXT: [[LEN:%.*]] = load i32, i32* [[LEN_PTR:%.*]], align 4 ; CHECK-NEXT: [[LEN_ADD_5:%.*]] = add i32 [[LEN]], -5 ; CHECK-NEXT: [[ENTRY_COND_0:%.*]] = icmp slt i32 [[LEN]], -2147483643 ; CHECK-NEXT: [[ENTRY_COND_1:%.*]] = icmp slt i32 -6, [[LEN_ADD_5]] ; CHECK-NEXT: [[ENTRY_COND:%.*]] = and i1 [[ENTRY_COND_0]], [[ENTRY_COND_1]] ; CHECK-NEXT: br i1 [[ENTRY_COND]], label [[LOOP_PREHEADER:%.*]], label [[LEAVE:%.*]] ; CHECK: loop.preheader: ; CHECK-NEXT: [[TMP0:%.*]] = icmp sgt i32 [[LEN]], 0 ; CHECK-NEXT: [[SMAX:%.*]] = select i1 [[TMP0]], i32 [[LEN]], i32 0 ; CHECK-NEXT: [[TMP1:%.*]] = add nsw i32 [[SMAX]], -5 ; CHECK-NEXT: br label [[LOOP:%.*]] ; CHECK: loop: ; CHECK-NEXT: [[IV:%.*]] = phi i32 [ [[IV_INC:%.*]], [[BE:%.*]] ], [ -6, [[LOOP_PREHEADER]] ] ; CHECK-NEXT: call void @side_effect() ; CHECK-NEXT: [[IV_INC]] = add nsw i32 [[IV]], 1 ; CHECK-NEXT: br i1 true, label [[BE]], label [[LEAVE_LOOPEXIT:%.*]] ; CHECK: be: ; CHECK-NEXT: call void @side_effect() ; CHECK-NEXT: [[EXITCOND:%.*]] = icmp ne i32 [[IV_INC]], [[TMP1]] ; CHECK-NEXT: br i1 [[EXITCOND]], label [[LOOP]], label [[LEAVE_LOOPEXIT]] ; CHECK: leave.loopexit: ; CHECK-NEXT: br label [[LEAVE]] ; CHECK: leave: ; CHECK-NEXT: ret void ; entry: %len = load i32, i32* %len.ptr %len.add.5 = add i32 %len, -5 %entry.cond.0 = icmp slt i32 %len, 2147483653 ;; 2147483653 == INT_MIN - (-5) %entry.cond.1 = icmp slt i32 -6, %len.add.5 %entry.cond = and i1 %entry.cond.0, %entry.cond.1 br i1 %entry.cond, label %loop, label %leave loop: %iv.2 = phi i32 [ 0, %entry ], [ %iv.2.inc, %be ] %iv = phi i32 [ -6, %entry ], [ %iv.inc, %be ] call void @side_effect() %iv.inc = add i32 %iv, 1 %iv.2.inc = add i32 %iv.2, 1 %iv.cmp = icmp slt i32 %iv, %len.add.5 ; Deduces {-5,+,1} s< (-5 + %len) from {0,+,1} < %len ; since %len s< INT_MIN - (-5) from the entry condition br i1 %iv.cmp, label %be, label %leave be: call void @side_effect() %be.cond = icmp slt i32 %iv.2, %len br i1 %be.cond, label %loop, label %leave leave: ret void } define i1 @func_18(i16* %tmp20, i32* %len.addr) { ; CHECK-LABEL: @func_18( ; CHECK-NEXT: entry: ; CHECK-NEXT: [[LEN:%.*]] = load i32, i32* [[LEN_ADDR:%.*]], align 4, [[RNG0]] ; CHECK-NEXT: [[TMP18:%.*]] = icmp eq i32 [[LEN]], 0 ; CHECK-NEXT: br i1 [[TMP18]], label [[BB2:%.*]], label [[BB0_PREHEADER:%.*]] ; CHECK: bb0.preheader: ; CHECK-NEXT: br label [[BB0:%.*]] ; CHECK: bb0: ; CHECK-NEXT: [[VAR_0_IN:%.*]] = phi i32 [ [[VAR_0:%.*]], [[BB1:%.*]] ], [ [[LEN]], [[BB0_PREHEADER]] ] ; CHECK-NEXT: [[VAR_1:%.*]] = phi i32 [ [[TMP30:%.*]], [[BB1]] ], [ 0, [[BB0_PREHEADER]] ] ; CHECK-NEXT: [[VAR_0]] = add nsw i32 [[VAR_0_IN]], -1 ; CHECK-NEXT: br i1 true, label [[STAY:%.*]], label [[BB2_LOOPEXIT:%.*]] ; CHECK: stay: ; CHECK-NEXT: [[TMP25:%.*]] = getelementptr inbounds i16, i16* [[TMP20:%.*]], i32 [[VAR_1]] ; CHECK-NEXT: [[TMP26:%.*]] = load i16, i16* [[TMP25]], align 2 ; CHECK-NEXT: [[TMP29:%.*]] = icmp eq i16 [[TMP26]], 0 ; CHECK-NEXT: br i1 [[TMP29]], label [[BB1]], label [[BB2_LOOPEXIT]] ; CHECK: bb1: ; CHECK-NEXT: [[TMP30]] = add nuw i32 [[VAR_1]], 1 ; CHECK-NEXT: [[TMP31:%.*]] = icmp eq i32 [[VAR_0]], 0 ; CHECK-NEXT: br i1 [[TMP31]], label [[BB3:%.*]], label [[BB0]] ; CHECK: bb2.loopexit: ; CHECK-NEXT: br label [[BB2]] ; CHECK: bb2: ; CHECK-NEXT: ret i1 false ; CHECK: bb3: ; CHECK-NEXT: ret i1 true ; entry: %len = load i32, i32* %len.addr, !range !0 %tmp18 = icmp eq i32 %len, 0 br i1 %tmp18, label %bb2, label %bb0.preheader bb0.preheader: br label %bb0 bb0: %var_0.in = phi i32 [ %var_0, %bb1 ], [ %len, %bb0.preheader ] %var_1 = phi i32 [ %tmp30, %bb1 ], [ 0, %bb0.preheader ] %var_0 = add nsw i32 %var_0.in, -1 %tmp23 = icmp ult i32 %var_1, %len br i1 %tmp23, label %stay, label %bb2 stay: %tmp25 = getelementptr inbounds i16, i16* %tmp20, i32 %var_1 %tmp26 = load i16, i16* %tmp25 %tmp29 = icmp eq i16 %tmp26, 0 br i1 %tmp29, label %bb1, label %bb2 bb1: %tmp30 = add i32 %var_1, 1 %tmp31 = icmp eq i32 %var_0, 0 br i1 %tmp31, label %bb3, label %bb0 bb2: ret i1 false bb3: ret i1 true } define void @func_19(i32* %length.ptr) { ; CHECK-LABEL: @func_19( ; CHECK-NEXT: entry: ; CHECK-NEXT: [[LENGTH:%.*]] = load i32, i32* [[LENGTH_PTR:%.*]], align 4, [[RNG0]] ; CHECK-NEXT: [[LENGTH_IS_NONZERO:%.*]] = icmp ne i32 [[LENGTH]], 0 ; CHECK-NEXT: br i1 [[LENGTH_IS_NONZERO]], label [[LOOP_PREHEADER:%.*]], label [[LEAVE:%.*]] ; CHECK: loop.preheader: ; CHECK-NEXT: br label [[LOOP:%.*]] ; CHECK: loop: ; CHECK-NEXT: [[IV:%.*]] = phi i32 [ [[IV_INC:%.*]], [[BE:%.*]] ], [ 0, [[LOOP_PREHEADER]] ] ; CHECK-NEXT: [[IV_INC]] = add nuw nsw i32 [[IV]], 1 ; CHECK-NEXT: br i1 true, label [[BE]], label [[LEAVE_LOOPEXIT:%.*]] ; CHECK: be: ; CHECK-NEXT: call void @side_effect() ; CHECK-NEXT: [[EXITCOND:%.*]] = icmp ne i32 [[IV_INC]], [[LENGTH]] ; CHECK-NEXT: br i1 [[EXITCOND]], label [[LOOP]], label [[LEAVE_LOOPEXIT]] ; CHECK: leave.loopexit: ; CHECK-NEXT: br label [[LEAVE]] ; CHECK: leave: ; CHECK-NEXT: ret void ; entry: %length = load i32, i32* %length.ptr, !range !0 %length.is.nonzero = icmp ne i32 %length, 0 br i1 %length.is.nonzero, label %loop, label %leave loop: %iv = phi i32 [ 0, %entry ], [ %iv.inc, %be ] %iv.inc = add i32 %iv, 1 %range.check = icmp ult i32 %iv, %length br i1 %range.check, label %be, label %leave be: call void @side_effect() %be.cond = icmp slt i32 %iv.inc, %length br i1 %be.cond, label %loop, label %leave leave: ret void } ; Like @func_19, but %length is no longer provably positive, so ; %range.check cannot be proved to be always true. define void @func_20(i32* %length.ptr) { ; CHECK-LABEL: @func_20( ; CHECK-NEXT: entry: ; CHECK-NEXT: [[LENGTH:%.*]] = load i32, i32* [[LENGTH_PTR:%.*]], align 4 ; CHECK-NEXT: [[LENGTH_IS_NONZERO:%.*]] = icmp ne i32 [[LENGTH]], 0 ; CHECK-NEXT: br i1 [[LENGTH_IS_NONZERO]], label [[LOOP_PREHEADER:%.*]], label [[LEAVE:%.*]] ; CHECK: loop.preheader: ; CHECK-NEXT: [[TMP0:%.*]] = icmp sgt i32 [[LENGTH]], 1 ; CHECK-NEXT: [[SMAX:%.*]] = select i1 [[TMP0]], i32 [[LENGTH]], i32 1 ; CHECK-NEXT: br label [[LOOP:%.*]] ; CHECK: loop: ; CHECK-NEXT: [[IV:%.*]] = phi i32 [ [[IV_INC:%.*]], [[BE:%.*]] ], [ 0, [[LOOP_PREHEADER]] ] ; CHECK-NEXT: [[IV_INC]] = add nuw nsw i32 [[IV]], 1 ; CHECK-NEXT: [[EXITCOND:%.*]] = icmp ne i32 [[IV]], [[LENGTH]] ; CHECK-NEXT: br i1 [[EXITCOND]], label [[BE]], label [[LEAVE_LOOPEXIT:%.*]] ; CHECK: be: ; CHECK-NEXT: call void @side_effect() ; CHECK-NEXT: [[EXITCOND1:%.*]] = icmp ne i32 [[IV_INC]], [[SMAX]] ; CHECK-NEXT: br i1 [[EXITCOND1]], label [[LOOP]], label [[LEAVE_LOOPEXIT]] ; CHECK: leave.loopexit: ; CHECK-NEXT: br label [[LEAVE]] ; CHECK: leave: ; CHECK-NEXT: ret void ; entry: %length = load i32, i32* %length.ptr %length.is.nonzero = icmp ne i32 %length, 0 br i1 %length.is.nonzero, label %loop, label %leave loop: %iv = phi i32 [ 0, %entry ], [ %iv.inc, %be ] %iv.inc = add i32 %iv, 1 %range.check = icmp ult i32 %iv, %length br i1 %range.check, label %be, label %leave be: call void @side_effect() %be.cond = icmp slt i32 %iv.inc, %length br i1 %be.cond, label %loop, label %leave leave: ret void } ; This checks that the backedge condition, (I + 1) < Length - 1 implies ; (I + 1) < Length define void @func_21(i32* %length.ptr) { ; CHECK-LABEL: @func_21( ; CHECK-NEXT: entry: ; CHECK-NEXT: [[LENGTH:%.*]] = load i32, i32* [[LENGTH_PTR:%.*]], align 4, [[RNG0]] ; CHECK-NEXT: [[LIM:%.*]] = sub i32 [[LENGTH]], 1 ; CHECK-NEXT: [[ENTRY_COND:%.*]] = icmp sgt i32 [[LENGTH]], 1 ; CHECK-NEXT: br i1 [[ENTRY_COND]], label [[LOOP_PREHEADER:%.*]], label [[LEAVE:%.*]] ; CHECK: loop.preheader: ; CHECK-NEXT: br label [[LOOP:%.*]] ; CHECK: loop: ; CHECK-NEXT: [[IV:%.*]] = phi i32 [ [[IV_INC:%.*]], [[BE:%.*]] ], [ 0, [[LOOP_PREHEADER]] ] ; CHECK-NEXT: [[IV_INC]] = add nuw nsw i32 [[IV]], 1 ; CHECK-NEXT: br i1 true, label [[BE]], label [[LEAVE_LOOPEXIT:%.*]] ; CHECK: be: ; CHECK-NEXT: call void @side_effect() ; CHECK-NEXT: [[EXITCOND:%.*]] = icmp ne i32 [[IV_INC]], [[LIM]] ; CHECK-NEXT: br i1 [[EXITCOND]], label [[LOOP]], label [[LEAVE_LOOPEXIT]] ; CHECK: leave.loopexit: ; CHECK-NEXT: br label [[LEAVE]] ; CHECK: leave: ; CHECK-NEXT: ret void ; entry: %length = load i32, i32* %length.ptr, !range !0 %lim = sub i32 %length, 1 %entry.cond = icmp sgt i32 %length, 1 br i1 %entry.cond, label %loop, label %leave loop: %iv = phi i32 [ 0, %entry ], [ %iv.inc, %be ] %iv.inc = add i32 %iv, 1 %range.check = icmp slt i32 %iv, %length br i1 %range.check, label %be, label %leave be: call void @side_effect() %be.cond = icmp slt i32 %iv.inc, %lim br i1 %be.cond, label %loop, label %leave leave: ret void } ; This checks that the backedge condition, (I + 1) < Length - 1 implies ; (I + 1) < Length define void @func_22(i32* %length.ptr) { ; CHECK-LABEL: @func_22( ; CHECK-NEXT: entry: ; CHECK-NEXT: [[LENGTH:%.*]] = load i32, i32* [[LENGTH_PTR:%.*]], align 4, [[RNG0]] ; CHECK-NEXT: [[ENTRY_COND:%.*]] = icmp sgt i32 [[LENGTH]], 1 ; CHECK-NEXT: br i1 [[ENTRY_COND]], label [[LOOP_PREHEADER:%.*]], label [[LEAVE:%.*]] ; CHECK: loop.preheader: ; CHECK-NEXT: br label [[LOOP:%.*]] ; CHECK: loop: ; CHECK-NEXT: [[IV:%.*]] = phi i32 [ [[IV_INC:%.*]], [[BE:%.*]] ], [ 0, [[LOOP_PREHEADER]] ] ; CHECK-NEXT: [[IV_INC]] = add nuw nsw i32 [[IV]], 1 ; CHECK-NEXT: br i1 true, label [[BE]], label [[LEAVE_LOOPEXIT:%.*]] ; CHECK: be: ; CHECK-NEXT: call void @side_effect() ; CHECK-NEXT: [[EXITCOND:%.*]] = icmp ne i32 [[IV_INC]], [[LENGTH]] ; CHECK-NEXT: br i1 [[EXITCOND]], label [[LOOP]], label [[LEAVE_LOOPEXIT]] ; CHECK: leave.loopexit: ; CHECK-NEXT: br label [[LEAVE]] ; CHECK: leave: ; CHECK-NEXT: ret void ; entry: %length = load i32, i32* %length.ptr, !range !0 %lim = sub i32 %length, 1 %entry.cond = icmp sgt i32 %length, 1 br i1 %entry.cond, label %loop, label %leave loop: %iv = phi i32 [ 0, %entry ], [ %iv.inc, %be ] %iv.inc = add i32 %iv, 1 %range.check = icmp sle i32 %iv, %length br i1 %range.check, label %be, label %leave be: call void @side_effect() %be.cond = icmp sle i32 %iv.inc, %lim br i1 %be.cond, label %loop, label %leave leave: ret void } define void @func_23(i32* %length.ptr) { ; CHECK-LABEL: @func_23( ; CHECK-NEXT: entry: ; CHECK-NEXT: [[LENGTH:%.*]] = load i32, i32* [[LENGTH_PTR:%.*]], align 4, [[RNG0]] ; CHECK-NEXT: [[ENTRY_COND:%.*]] = icmp ult i32 4, [[LENGTH]] ; CHECK-NEXT: br i1 [[ENTRY_COND]], label [[LOOP_PREHEADER:%.*]], label [[LEAVE:%.*]] ; CHECK: loop.preheader: ; CHECK-NEXT: br label [[LOOP:%.*]] ; CHECK: loop: ; CHECK-NEXT: [[IV:%.*]] = phi i32 [ [[IV_INC:%.*]], [[BE:%.*]] ], [ 4, [[LOOP_PREHEADER]] ] ; CHECK-NEXT: [[IV_INC]] = add nuw nsw i32 [[IV]], 1 ; CHECK-NEXT: br i1 true, label [[BE]], label [[LEAVE_LOOPEXIT:%.*]] ; CHECK: be: ; CHECK-NEXT: call void @side_effect() ; CHECK-NEXT: [[EXITCOND:%.*]] = icmp ne i32 [[IV_INC]], [[LENGTH]] ; CHECK-NEXT: br i1 [[EXITCOND]], label [[LOOP]], label [[LEAVE_LOOPEXIT]] ; CHECK: leave.loopexit: ; CHECK-NEXT: br label [[LEAVE]] ; CHECK: leave: ; CHECK-NEXT: ret void ; entry: %length = load i32, i32* %length.ptr, !range !0 %entry.cond = icmp ult i32 4, %length br i1 %entry.cond, label %loop, label %leave loop: %iv = phi i32 [ 4, %entry ], [ %iv.inc, %be ] %iv.inc = add i32 %iv, 1 %range.check = icmp slt i32 %iv, %length br i1 %range.check, label %be, label %leave be: call void @side_effect() %be.cond = icmp slt i32 %iv.inc, %length br i1 %be.cond, label %loop, label %leave leave: ret void } define void @func_24(i32* %init.ptr) { ; CHECK-LABEL: @func_24( ; CHECK-NEXT: entry: ; CHECK-NEXT: [[INIT:%.*]] = load i32, i32* [[INIT_PTR:%.*]], align 4, [[RNG0]] ; CHECK-NEXT: [[ENTRY_COND:%.*]] = icmp ugt i32 [[INIT]], 4 ; CHECK-NEXT: br i1 [[ENTRY_COND]], label [[LOOP_PREHEADER:%.*]], label [[LEAVE:%.*]] ; CHECK: loop.preheader: ; CHECK-NEXT: br label [[LOOP:%.*]] ; CHECK: loop: ; CHECK-NEXT: [[IV:%.*]] = phi i32 [ [[IV_DEC:%.*]], [[BE:%.*]] ], [ [[INIT]], [[LOOP_PREHEADER]] ] ; CHECK-NEXT: [[IV_DEC]] = add nsw i32 [[IV]], -1 ; CHECK-NEXT: br i1 true, label [[BE]], label [[LEAVE_LOOPEXIT:%.*]] ; CHECK: be: ; CHECK-NEXT: call void @side_effect() ; CHECK-NEXT: [[BE_COND:%.*]] = icmp sgt i32 [[IV_DEC]], 4 ; CHECK-NEXT: br i1 [[BE_COND]], label [[LOOP]], label [[LEAVE_LOOPEXIT]] ; CHECK: leave.loopexit: ; CHECK-NEXT: br label [[LEAVE]] ; CHECK: leave: ; CHECK-NEXT: ret void ; entry: %init = load i32, i32* %init.ptr, !range !0 %entry.cond = icmp ugt i32 %init, 4 br i1 %entry.cond, label %loop, label %leave loop: %iv = phi i32 [ %init, %entry ], [ %iv.dec, %be ] %iv.dec = add i32 %iv, -1 %range.check = icmp sgt i32 %iv, 4 br i1 %range.check, label %be, label %leave be: call void @side_effect() %be.cond = icmp sgt i32 %iv.dec, 4 br i1 %be.cond, label %loop, label %leave leave: ret void } declare i1 @cond_func() define i32 @func_25(i32 %start) { ; CHECK-LABEL: @func_25( ; CHECK-NEXT: entry: ; CHECK-NEXT: br label [[LOOP:%.*]] ; CHECK: loop: ; CHECK-NEXT: [[IV:%.*]] = phi i32 [ [[START:%.*]], [[ENTRY:%.*]] ], [ [[IV_NEXT:%.*]], [[BACKEDGE:%.*]] ] ; CHECK-NEXT: [[C1:%.*]] = icmp ne i32 [[IV]], 0 ; CHECK-NEXT: br i1 [[C1]], label [[CHECKED_1:%.*]], label [[FAIL:%.*]] ; CHECK: checked.1: ; CHECK-NEXT: [[C2:%.*]] = icmp ne i32 [[IV]], 0 ; CHECK-NEXT: br i1 [[C2]], label [[CHECKED_2:%.*]], label [[FAIL]] ; CHECK: checked.2: ; CHECK-NEXT: [[C3:%.*]] = icmp ne i32 [[IV]], 0 ; CHECK-NEXT: br i1 [[C3]], label [[BACKEDGE]], label [[FAIL]] ; CHECK: backedge: ; CHECK-NEXT: [[IV_NEXT]] = add i32 [[IV]], 758394 ; CHECK-NEXT: [[LOOP_COND:%.*]] = call i1 @cond_func() ; CHECK-NEXT: br i1 [[LOOP_COND]], label [[LOOP]], label [[EXIT:%.*]] ; CHECK: fail: ; CHECK-NEXT: unreachable ; CHECK: exit: ; CHECK-NEXT: [[IV_LCSSA1:%.*]] = phi i32 [ [[IV]], [[BACKEDGE]] ] ; CHECK-NEXT: ret i32 [[IV_LCSSA1]] ; entry: br label %loop loop: %iv = phi i32 [%start, %entry], [%iv.next, %backedge] %c1 = icmp ne i32 %iv, 0 br i1 %c1, label %checked.1, label %fail checked.1: %c2 = icmp ne i32 %iv, 0 br i1 %c2, label %checked.2, label %fail checked.2: %c3 = icmp ne i32 %iv, 0 br i1 %c3, label %backedge, label %fail backedge: %iv.next = add i32 %iv, 758394 %loop.cond = call i1 @cond_func() br i1 %loop.cond, label %loop, label %exit fail: unreachable exit: ret i32 %iv } define i32 @func_26(i32 %start) { ; CHECK-LABEL: @func_26( ; CHECK-NEXT: entry: ; CHECK-NEXT: br label [[LOOP:%.*]] ; CHECK: loop: ; CHECK-NEXT: [[IV:%.*]] = phi i32 [ [[START:%.*]], [[ENTRY:%.*]] ], [ [[IV_NEXT:%.*]], [[BACKEDGE:%.*]] ] ; CHECK-NEXT: [[C1:%.*]] = icmp slt i32 [[IV]], 0 ; CHECK-NEXT: br i1 [[C1]], label [[CHECKED_1:%.*]], label [[FAIL:%.*]] ; CHECK: checked.1: ; CHECK-NEXT: [[C2:%.*]] = icmp slt i32 [[IV]], 1 ; CHECK-NEXT: br i1 [[C2]], label [[CHECKED_2:%.*]], label [[FAIL]] ; CHECK: checked.2: ; CHECK-NEXT: [[C3:%.*]] = icmp slt i32 [[IV]], 2 ; CHECK-NEXT: br i1 [[C3]], label [[BACKEDGE]], label [[FAIL]] ; CHECK: backedge: ; CHECK-NEXT: [[IV_NEXT]] = add i32 [[IV]], 758394 ; CHECK-NEXT: [[LOOP_COND:%.*]] = call i1 @cond_func() ; CHECK-NEXT: br i1 [[LOOP_COND]], label [[LOOP]], label [[EXIT:%.*]] ; CHECK: fail: ; CHECK-NEXT: unreachable ; CHECK: exit: ; CHECK-NEXT: [[IV_LCSSA1:%.*]] = phi i32 [ [[IV]], [[BACKEDGE]] ] ; CHECK-NEXT: ret i32 [[IV_LCSSA1]] ; entry: br label %loop loop: %iv = phi i32 [%start, %entry], [%iv.next, %backedge] %c1 = icmp slt i32 %iv, 0 br i1 %c1, label %checked.1, label %fail checked.1: %c2 = icmp slt i32 %iv, 1 br i1 %c2, label %checked.2, label %fail checked.2: %c3 = icmp slt i32 %iv, 2 br i1 %c3, label %backedge, label %fail backedge: %iv.next = add i32 %iv, 758394 %loop.cond = call i1 @cond_func() br i1 %loop.cond, label %loop, label %exit fail: unreachable exit: ret i32 %iv } !0 = !{i32 0, i32 2147483647}